Shearing tools find a wide range of applications in our daily life. One type of the shearing tools is scissors. Scissors are hand-operated shearing tools. There are many forms of scissors designed for different purposes available in the market. Types of scissors range from office scissors for cutting thin materials such as paper, cardboard and rope, to kitchen scissors for cutting bones and flesh as well as other specialized scissors for cutting hair, wire, cloth, bandage etc. Conventional scissors usually include two cutting members, each with a blade portion at one end and a handle portion at the other end. In general, the two cutting members crossed at a pivot positioned at the middle of the scissors. The two blade portions of the cutting members can pivotally move away from and towards each other in an open position and a closed position to cut an object to be cut.
Mechanically, conventional scissors are a first-class lever with the pivot acting as the fulcrum. When cutting thick or hard materials such as thick cardboards and bones, it is common for the operator to move the object to be cut as close to the fulcrum as possible to maximize the mechanical advantage of the lever. However, even so, the force required for cutting thick and strong material with conventional scissors is big and it is difficult and tiring for the operator especially during continues and repeating operation of the scissors.
On the other hand, some specialized scissors, such as kitchen scissors required to be washed and cleaned every time after use. However, the blades of conventional scissors are usually either fixedly attached to each other or detachably attached by pivot screw. This not only requires the use of tool for removing and replacing the blades, but also removing and replacing the screw may alter the position of the blade and affect the cutting action of the blades.
Therefore, there is a need for a shearing tool that is operated easier and faster and required less force by the operator when in use and a shearing tool that can be separated and replaced conveniently without the use of tools.